1. Field of the Invention
The present invention relates to an electrical or optical timing apparatus capable of serving as a timing connector or a timing indicator or a combination thereof.
2. Description of the Prior Art
Although a variety of timing devices have been proposed and used heretofore, there does not exist a low-cost device suited for driving radio or television sets. Of late, there are available replacements for the conventional receivers of a mechanical switching system especially with respect to the selection of a channel. Electronic tuner type radio and television sets employing a purely electrical switching system are commercially available. Using the electronic tuner has the features of requiring no power and achieving immediate selection of a desired channel. With regard to all electric apparatus including radio and television sets, it seems to be the general trend that such features of no power requirement and sequential operation gradually extend the kind and scope of applications in accordance with the progress of electronic circuits. It is also one of the recent trends that, a single timing device is used for driving many electric circuits or apparatus at desired times in an interrelated and programmed sequence; for example, in selective reception of multiple radio and television channels.
Among the conventional timing connectors capable of performing programmed driving operation, there are many types which are known including type that effects mechanical timing connection by the use of a cam, the type that causes electrical slide contact of segments by a rotating brush, the digital type employing a relay circuit, and the electronic type using a digital logic circuit. Each of the above devices have both merits and faults. Namely, the one utilizing a cam is superior with respect to the ease of attaining a simple mechanism and large driving power but has a fault in maintaining drive time accuracy during a long period. The one causing electrical slide contact has a fault in service life. The optical one has, in most cases, some difficulties with time accuracy and program change. The one with a relay becomes bulky in structure. And the electronic one with a digital logic circuit is expensive, though it may be nearly universal with high accuracy and a performance superior to any of other types. Thus, there has not yet appeared any convenient, low-cost device that is equipped with a timing plate capable of presetting and changing a complicated program and permitting ready confirmation of the setting state.